Autonomous system
AS11004 CITY-OF-GOLDEN-01
Unclassified ARIN
Summary
City of Golden
government legacy
CITY-OF-GOLDEN-01 is the municipal network of the City of Golden, Colorado, the county seat of Jefferson County just west of Denver. ARIN registers the ASN to the city at 911 10th Street, Golden, with the city's IT department as the administrative contact.
What it's used for
This is a single-purpose local-government AS. RIS sees exactly 1 announced IPv4 prefix, 23.161.120.0/24, carrying 256 addresses, no IPv6, and 1 observed neighbour. That is the smallest routable footprint an organisation can have while still holding its own AS number, and the single upstream tells you why it exists: not to sell transit or to peer widely, but to let the city keep its own address space and re-home it between providers without renumbering. The traffic behind a municipal /24 like this is city-hall infrastructure, public-facing city services and staff connectivity, not residential subscribers.
Notable
The one announced prefix registers to CITYOFGOLDEN-IPV4-01, the city's own ARIN handle, so holder and registrant agree and there is nothing leased or brokered in the inventory.
Interesting
Despite the low AS number, this is not a 1990s allocation. ARIN registered the org record in October 2019 and the ASN itself in February 2020, and the announced 23.161.120.0/24 sits in modern ARIN space rather than the legacy swamp. AS11004 is a recycled number: it was returned by whoever held it before and reissued to Golden, so its number says nothing about the age of the network behind it.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Interconnection
Peering at a glance
Internet exchanges
No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.
Transit providers
1 upstream, 0 downstream and 1 adjacent networks observed; most-used upstreams first.
| AS | Network | Paths seen |
|---|---|---|
| AS33652 | Comcast Cable Communications, LLC | 60 |
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-27, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 1 prefixes · 256 addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 1 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS11004- Registry name
- CITY-OF-GOLDEN-01
- Registrant
- City of Golden
- Abuse contact
- itnotifications@cityofgolden.net
- Registered
- 2020-02-04
- Last changed
- 2020-02-04
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 100% valid · 1 valid, 0 with no ROA
- ROAs
- 2 authorising AS11004
- ASPA
- no ASPA record
- IRR
- 100% registered · 1 of 1 announcements
- Route objects
- 1 naming AS11004
Reputation
Classification and threat
Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.
Spamhaus DROP
Not on ASN-DROP The network as a whole is not listed.
No DROP prefixes None of its announced space is on the DROP prefix list.
Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 447 networks and 1,852 prefixes, as published 2026-10-27. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.
FBI IC3
No IC3 indicators Nothing from the FBI IC3 feed.
IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere